Bearing support assembly

ABSTRACT

A bearing support assembly to support one or more bearings on a shaft. The bearing support assembly includes a bearing support frame configured to be coupled to a static frame, a plurality of ribs connected to the bearing support frame, and a bearing support connected to the plurality of ribs and configured to support a bearing of the one or more bearings. The bearing support assembly has a non-axisymmetric stiffness around a circumference of the bearing support assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of Indian Patent ApplicationNo. 202111039755, filed on Sep. 2, 2021, which is hereby incorporated byreference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates to bearing support assemblies for acompressor section of an engine.

BACKGROUND

Gas turbine engines include rotating shafts for rotation of variouscoupled components. For example, gas turbine engines include highpressure shafts for driving high pressure compressors and low pressureshafts for driving low pressure compressors. The shafts are supportedwithin the compressor section via a plurality of bearings. A bearingsupport assembly supports the bearings about the shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the present disclosure will be apparent fromthe following, more particular, description of various exemplaryembodiments, as illustrated in the accompanying drawings, wherein likereference numbers generally indicate identical, functionally similar,and/or structurally similar elements.

FIG. 1 shows a schematic, cross-sectional view of an engine, taken alonga centerline of the engine, according to an embodiment of the presentdisclosure.

FIG. 2A shows a schematic, partial cross-sectional view of a bearingsupport assembly with bearings and a shaft for use in an engine, takenalong a centerline of the engine, according to an embodiment of thepresent disclosure.

FIG. 2B shows a schematic, partial perspective cross-sectional view ofthe bearing support assembly of FIG. 2A, taken along a centerline of theengine, according to an embodiment of the present disclosure.

FIG. 3A shows a schematic view describing the stiffness of a bearingsupport assembly, according to an embodiment of the present disclosure.

FIG. 3B shows a schematic view describing the stiffness of a bearingsupport assembly, according to an embodiment of the present disclosure.

FIG. 4A shows a graph of the stiffness of a bearing support assemblyaround the circumference of the bearing support, according to anembodiment of the present disclosure.

FIG. 4B shows a graph of the stiffness of a bearing support assemblyaround the circumference of the bearing support, according to anembodiment of the present disclosure.

FIG. 4C shows a graph of the stiffness of a bearing support assemblyaround the circumference of the bearing support, according to anembodiment of the present disclosure.

FIG. 4D shows a graph of the stiffness of a bearing support assemblyaround the circumference of the bearing support, according to anembodiment of the present disclosure.

FIG. 5 shows a schematic, perspective view of a bearing supportassembly, according to an embodiment of the present disclosure.

FIG. 6 shows a schematic, front end cross-sectional view of the bearingsupport assembly of FIG. 5 with bearings and a shaft, according to anembodiment of the present disclosure.

FIG. 7 shows a schematic, cross-sectional view of a rib of a bearingsupport assembly, taken along a plane extending in the radial direction,according to an embodiment of the present disclosure.

FIG. 8 shows a schematic, cross-sectional view of a rib of a bearingsupport assembly, taken along a plane extending in the radial direction,according to an embodiment of the present disclosure.

FIG. 9 shows a schematic, perspective view of a bearing supportassembly, according to an embodiment of the present disclosure.

FIG. 10A shows a schematic, cross-sectional view of a rib of a bearingsupport assembly, taken along a centerline of the rib, according to anembodiment of the present disclosure.

FIG. 10B shows a schematic, cross-sectional view of a rib of a bearingsupport assembly, taken along a centerline of the rib, according to anembodiment of the present disclosure.

FIG. 10C shows a schematic, cross-sectional view of a rib of a bearingsupport assembly, taken along a centerline of the rib, according to anembodiment of the present disclosure.

FIG. 11 shows a schematic, perspective view of a bearing supportassembly, according to an embodiment of the present disclosure.

FIG. 12 shows a schematic, front end cross-sectional view of the bearingsupport assembly of FIG. 11 , according to an embodiment of the presentdisclosure.

FIG. 13 shows a schematic, perspective view of a bearing support,according to an embodiment of the present disclosure.

FIG. 14 shows a schematic, perspective view of a bearing support,according to an embodiment of the present disclosure.

FIG. 15 shows a schematic, perspective view of a bearing support,according to an embodiment of the present disclosure.

FIG. 16 shows a schematic, perspective view of a bearing support,according to an embodiment of the present disclosure.

FIG. 17A shows a schematic, perspective view of a bearing support,according to an embodiment of the present disclosure.

FIG. 17B shows a schematic end view of the bearing support of FIG. 17A,according to an embodiment of the present disclosure.

FIG. 17C shows a schematic, cross-sectional view of a rib of the bearingsupport of FIG. 17A, taken along a plane extending in the radialdirection of FIG. 17A, according to an embodiment of the presentdisclosure.

FIG. 18 shows a schematic, front end cross-sectional view of a bearingsupport assembly with bearings and a shaft, according to an embodimentof the present disclosure.

FIG. 19 shows a schematic side, cross-sectional view of a bearingsupport assembly, taken along a centerline of an engine, according to anembodiment of the present disclosure.

FIG. 20 shows a schematic side, cross-sectional view of a bearingsupport assembly, taken along a centerline of an engine, according to anembodiment of the present disclosure.

FIG. 21 shows a graph of the stiffness of a bearing support assembly asa function of load applied to the bearing support assembly, according toan embodiment of the present disclosure.

FIG. 22 shows a schematic, front end cross-sectional view of a bearingsupport assembly with bearings and a shaft, according to an embodimentof the present disclosure.

FIG. 23 shows a schematic side, cross-sectional view of a bearingsupport assembly, taken along a centerline of an engine, according to anembodiment of the present disclosure.

FIG. 24 shows a schematic side, cross-sectional view of a bearingsupport assembly, taken along a centerline of an engine, according to anembodiment of the present disclosure.

FIG. 25 shows a graph of the stiffness of a bearing support assembly asa function of load applied to the bearing support assembly, according toan embodiment of the present disclosure.

FIG. 26 shows a schematic side, cross-sectional view of a bearingsupport assembly, taken along a centerline of an engine, according to anembodiment of the present disclosure.

FIG. 27 shows a graph of the stiffness of a bearing support assembly asa function of load applied to the bearing support assembly, according toan embodiment of the present disclosure.

FIG. 28 shows a schematic cross-sectional view describing the stiffnessof a bearing support assembly, according to an embodiment of the presentdisclosure.

FIG. 29 shows a schematic cross-sectional view describing the stiffnessof a bearing support assembly, according to an embodiment of the presentdisclosure.

FIG. 30 shows a schematic side, cross-sectional view of a bearingsupport assembly, taken along a centerline of an engine, according to anembodiment of the present disclosure.

FIG. 31 shows a schematic end view of a bearing support assembly,according to an embodiment of the present disclosure.

FIG. 32 shows a schematic end view of a bearing support assembly,according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Features, advantages, and embodiments of the present disclosure are setforth or apparent from a consideration of the following detaileddescription, drawings, and claims. Moreover, it is to be understood thatthe following detailed description is exemplary and intended to providefurther explanation without limiting the scope of the disclosure asclaimed.

Various embodiments are discussed in detail below. While specificembodiments are discussed, this is done for illustration purposes only.A person skilled in the relevant art will recognize that othercomponents and configurations may be used without departing from thespirit and scope of the present disclosure.

The bearing support assembly of the present disclosure may allow forvarying the stiffness of the bearing support assembly in a 360°arrangement around the circumference of the bearing support assembly.This may allow for bearings in an X-axis direction (e.g., a threeo'clock position and a nine o'clock position) to have a first supportstiffness and the bearings in a Y-axis direction (e.g., a twelve o'clockposition and a six o'clock position) to have a second support stiffness.The support of the bearings, characterized by the stiffness of thebearing assembly, may be varied between the X-axis and Y-axis positions,may be constant between the X-axis and Y-axis positions, and/or may bevaried continuous around the circumference of the bearing support. Thestiffness may be continuously varying for all operating ranges and/ormay be a function of load applied to the bearing assembly. The stiffnessof the bearing support assembly may be varied through material,construction, orientation, thickness, shape, inclusion of gaps,orientation of ribs, etc., and any combination thereof. The stiffness ofthe bearing support assembly may be non-symmetric always or atpredetermined loads.

Referring to FIG. 1 an engine 10 has a longitudinal, axial centerline 12extending therethrough along an axial direction A. The engine 10 definesa radial direction R extending perpendicular from the centerline 12 anda circumferential direction C (shown in/out of the page in FIG. 1 )extends perpendicular to both the centerline 12 and the radial directionR. The engine 10 may be, for example, but not limited to, a gas turbineengine, a turbofan engine, an open rotor engine, a turboshaft engine,turbojet engine, or a turboprop configuration engine, including marineand industrial turbine engines and auxiliary power units.

The engine 10 includes a core engine 14 and a fan section 16 positionedupstream thereof. The core engine 14 generally includes an outer casing18 that defines an annular inlet 20. In addition, the outer casing 18may further enclose and support a low pressure compressor 22 forincreasing the pressure of the air that enters the core engine 14 to afirst pressure level. A multi-stage, axial-flow high pressure compressor24 may then receive the pressurized air from the low pressure compressor22 and further increase the pressure of such air. The pressurized airexiting the high pressure compressor 24 may then flow to a combustor 26within which fuel is injected into the flow of pressurized air, with theresulting mixture being combusted within the combustor 26. High energycombustion products 64 are directed from the combustor 26 along the hotgas path of the engine 10 to a high pressure turbine 28 for driving thehigh pressure compressor 24 via a high pressure shaft 30, also referredto as a shaft 30, and, then, to a low pressure turbine 32 for drivingthe low pressure compressor 22 and fan section 16 via a low pressureshaft 34 that is generally coaxial with high pressure shaft 30. Afterdriving each of the high pressure turbine 28 and the low pressureturbine 32, the combustion products 64 may be expelled from the coreengine 14 via an exhaust nozzle 36 to provide propulsive jet thrust.

Additionally, as shown in FIG. 1 , the fan section 16 of the engine 10includes a rotatable, axial-flow fan rotor 38 configured to besurrounded by an annular nacelle 42. In particular embodiments, the lowpressure shaft 34 may be connected directly to the fan rotor 38 or arotor disk 40, such as in a direct-drive configuration. In alternativeconfigurations, the low pressure shaft 34 may be connected to the fanrotor 38 via a speed reduction device such as a reduction gear gearboxin an indirect-drive or geared-drive configuration. Such speed reductiondevices may be included between any suitable shafts/spools within theengine 10 as desired or required. Additionally, the fan rotor 38 and/orrotor disk 40 may be enclosed or formed as part of a fan hub 44.

The nacelle 42 may be configured to be supported relative to the coreengine 14 by a plurality of substantially radially-extending,circumferentially-spaced outlet guide vanes 46. As such, the nacelle 42may enclose the fan rotor 38 and a plurality of fan blades 48. Each ofthe fan blades 48 may extend between a root and a tip in the radialdirection R relative to the centerline 12. A downstream section 50 ofthe nacelle 42 may extend over an outer portion of the core engine 14 soas to define a secondary airflow or bypass conduit 52 that providesadditional propulsive jet thrust.

During operation of the engine 10, an initial air flow 54 may enter theengine 10 through an inlet 56 of the nacelle 42. The air flow 54 thenpasses through the fan blades 48 and splits into a first compressed airflow 58 that moves through the bypass conduit 52 and a second compressedair flow 60 that enters the low pressure compressor 22. The pressure ofthe second compressed air flow 60 is then increased and enters the highpressure compressor 24 as air flow 62. After mixing with fuel and beingcombusted within the combustor 26, the combustion products 64 exit thecombustor 26 and flow through the high pressure turbine 28. Thereafter,the combustion products 64 flow through the low pressure turbine 32 andexit the exhaust nozzle 36 to provide thrust for the engine 10.

FIG. 2A shows a close-up view of a cross section of the compressorsection of the engine 10 (FIG. 1 ). FIG. 2B shows a perspective view ofthe close-up view of the compressor section of the engine 10 (FIG. 1 ).Referring to both FIGS. 2A and 2B, a forward end 66 of the high pressureshaft 30 is positioned within the compressor section of the engine 10,radially inward of a core air flow path 74 for the second compressed airflow 60 flowing through the core engine 14 (FIG. 1 ). The core air flowpath 74 is defined at least in part by a static frame 68 within thecompressor section of the engine 10. The static frame 68 may be a singlepiece unit or may be formed of a plurality of members attached together.

With continued reference to FIGS. 2A and 2B, the engine 10 includes abearing supporting rotation of the high pressure shaft 30 at the forwardend 66. For example, the engine 10 includes a forward bearing 70 and anaft bearing 72. Although shown at the forward end 66 of the highpressure shaft 30, the forward bearing 70 and/or the aft bearing 72 maybe included at any other position along the high pressure shaft 30,along the low pressure shaft 34 (FIG. 1 ), or any other suitablerotating shaft of the engine 10 or other suitable gas turbine engine.

FIGS. 2A and 2B show a bearing support assembly 76 for supporting theforward bearing 70, the aft bearing 72, or both the forward bearing 70and the aft bearing 72. The bearing support assembly 76 may include aframe 98, which may be a bearing support frame, coupled to a pluralityof individual beams or ribs 78. The ribs 78 may be spaced along acircumferential direction C of the frame 98 (see, for example, FIG. 5 ).Each of the ribs 78 may include an axial portion 79 that extends in theaxial direction A. Coupled to each of the axial portions 79 of the ribs78 may be a forward bearing support rib 80 and an aft bearing supportrib 82. The forward bearing support ribs 80 and the aft bearing supportribs 82 may extend in the radial direction R inward from the axialportion 79. Additionally, the aft bearing support ribs 82 may include anaxial member 84 extending generally along the axial direction A forsupporting the aft bearing 72. The bearing support 76 is attached to thestatic frame 68 at a first location 86 via a first attachment flange 88and at a second location 90 via a second attachment flange 92. Thebearing support 76 may be referred to as a “squirrel casing” or“squirrel cage” for the forward bearing 70 and the aft bearing 72.

With continued reference to FIGS. 2A and 2B, the bearing supportassembly 76 may support the forward bearing 70, the aft bearing 72, orboth the forward bearing 70 and the aft bearing 72 in their respectivebearing races adjacent the high pressure shaft 30. For example, thebearing support assembly 76 may support the forward bearing 70 within aforward bearing race 94. The support may be provided by the forwardbearing support ribs 80. The bearing support assembly 76 may support theaft bearing 72 within an aft bearing race 96. The support may beprovided by the aft bearing support ribs 82.

The bearing support assembly 76 may have a stiffness selected to supportthe forward bearing 70 and/or the aft bearing 72. For example, thebearing support 76, the ribs 78, the axial portion 79, the forwardbearing support ribs 80, the aft bearing support ribs 82, the frame 98,any portion thereof, or any combination thereof may be designed, sized,dimensioned, oriented, or shaped to provide a particular orpredetermined stiffness to the respective bearing.

In some examples, the stiffness of the bearing support assembly 76 maybe constant around the circumference of the bearing support assembly 76.In some examples, the stiffness may vary around the circumference of thebearing support assembly. For example, referring to FIGS. 3A and 3B, thebearing support assembly 76 may be supported by a rib 78 a located atthe twelve o'clock position (point A), a rib 78 b located at the threeo'clock position (point B), a rib 78 c located at the six o'clockposition (point C), and a rib 78 d located at the nine o'clock position(point D). In FIG. 3A, the stiffness K may be constant around thecircumference of the bearing support assembly 76. In FIG. 3B, thestiffness may vary at different points around the circumference of thebearing support assembly 76. For example, at point A and point C, thebearing support assembly 76 may have a first stiffness K₁ and at point Band point D, the bearing support assembly 76 may have a second stiffnessK₂. The first stiffness K₁ and the second stiffness K₂ may be different.In some examples, the stiffness may additionally, or alternatively, varybetween adjacent points (e.g., between points A and B, etc.), may varybetween points and be identical at points, may be constant betweenpoints, or combinations thereof.

Some exemplary variations of stiffness around the circumference of thebearing support assembly are shown in FIGS. 4A to 4D. For example, inFIG. 4A, the bearing support assembly may have a stiffness representedby a curve 150 a. That is, at a first point, K₁, around thecircumference of the bearing support assembly, the bearing supportassembly may provide a first stiffness, at a second point, K₂, aroundthe circumference of the bearing support assembly, the bearing supportassembly may provide a second stiffness, at a third point, K₃, aroundthe circumference of the bearing support assembly, the bearing supportassembly may provide a third stiffness, and at a fourth point, K₂,around the circumference of the bearing support assembly, the bearingsupport assembly may again provide the second stiffness. In someexamples, the first point K₁ may be located at twelve o'clock position(e.g., point A in FIG. 3A), the second point K₂ may be located at athree o'clock position (e.g., point B in FIG. 3A), the third point K₃may be located at a six o'clock position (e.g., point C in FIG. 3A), andthe fourth point K₂ may be located at a nine o'clock position (e.g.,point D in FIG. 3A). In this manner, the bearing support assembly mayexhibit the highest stiffness K₁ at the twelve o'clock position and mayexhibit the lowest stiffness K₃ at the six o'clock position. At thethree o'clock position and the nine o'clock position, a mean stiffnessK₂ is present. As shown in FIG. 4A, the stiffness may by constantlyvaried in a sinusoidal manner around the circumference of the bearingsupport assembly.

In another example, shown in FIG. 4B, the stiffness of the bearingsupport assembly may vary in a linear manner around the circumference ofthe bearing support assembly as represented by a curve 150 b. Thehighest stiffness K₁ may be exhibited at the twelve o'clock position andthe lowest stiffness K₃ may be exhibited at the six o'clock position. Amean stiffness K₂ may be exhibited at the three o'clock and nine o'clockpositions. In another example, shown in FIG. 4C, the stiffness of thebearing support assembly may vary in a linear manner around thecircumference of the bearing support assembly as represented by a curve150 c. The highest stiffness K₁ may be exhibited at the twelve o'clockposition and the lowest stiffness K₃ may be exhibited at the six o'clockposition. The mean stiffness K₂ may be exhibited at other points aroundthe circumference, such as, for example, the three o'clock position andthe nine o'clock position. In another example, shown in FIG. 4D, thestiffness of the bearing assembly may vary in a spline or curve aroundthe circumference of the bearing support assembly as represented by acurve 150 d. The spline or curve may be a curve of polynomial order(e.g., second order, third order, or higher order). For example, thehighest stiffness K₁ may be exhibited at the twelve o'clock position andthe lowest stiffness K₃ may be exhibited at the six o'clock position.The mean stiffness K₂ may be exhibited at the three o'clock position andthe nine o'clock position.

The examples of FIGS. 4A to 4D are merely exemplary and the stiffness ofthe bearing support assembly may be selected to vary in any location andin any pattern, array, or curve around the circumference of the bearingsupport assembly to achieve the desired support of the bearingassemblies. As can be seen in the present disclosure, for example, FIG.5 , additional ribs may be located between the depicted rib 78 a, rib 78b, rib 78 c, and rib 78 d. The stiffness K at each of the ribs may beselected to provide a particular support of the high pressure shaft 30by the bearing support assembly 76. The stiffness along thecircumference of the bearing support 76 may be varied.

FIGS. 5 to 32 represent exemplary manners in which to vary the stiffnessat a particular location, along a section of the circumference, and/oralong the entire circumference of the bearing support assembly. Any ofthe exemplary manners to vary the stiffness may be combined with othermanners of varying the stiffness as described herein. Any of theexemplary manners of FIGS. 5 to 32 may be varied in any of the mannersdescribed above, e.g., with respect to FIGS. 4A to 4D.

FIGS. 5 to 17C describe non-axisymmetric bearing support assemblies. Thebearing support assemblies of FIGS. 5 to 17C may have a bearing supportassembly that has a stiffness that is continuously varied for alloperating ranges of an engine.

FIGS. 5 to 8 show an exemplary bearing support assembly 100. The bearingsupport assembly 100 includes a plurality of ribs 104 spacedcircumferentially in a direction C around the bearing support assembly100. The plurality of ribs 104 may be located between a frame 102, alsoreferred to as a bearing support frame 102, and a bearing support 106. Afirst rib 104 a may be located at the twelve o'clock position (point A),a second rib 104 b may be located at the three o'clock position (pointB), a third rib 104 c may be located at the six o'clock position (pointC), and a fourth rib 104 d may be located at the nine o'clock position(point D). The bearing support assembly 100 may support a plurality ofbearings 108 located around the shaft 30.

As described previously, a stiffness may be varied around thecircumference of the bearing support assembly 100. In the example ofFIGS. 5 to 7 , the stiffness may be varied by altering or changing thematerial of the ribs 104. For example, the thickness of the ribs 104,the material of the ribs 104, and/or the cross section across thecircumference of the bearing support may be varied around thecircumference of the bearing support assembly 100 to vary the stiffnessof the bearing support assembly 100.

FIGS. 7 and 8 show bi-metallic beam arrangements for a variable elasticmodulus of the ribs 104. That is, the ribs 104 may be formed of a basematerial that is coated in a secondary material to vary the stiffness ofthe ribs 104. The variation may come via the selection of the secondarycoating material (e.g., higher strength for higher stiffness ribs 104vs. lower strength materials for lower stiffness ribs 104 and/or higherYoung's modulus for higher stiffness ribs 104 and a lower Young'smodulus for lower stiffness ribs 104) or via the thickness of theapplied coating (e.g., greater thickness for higher stiffness ribs 104vs. lower thickness for lower stiffness ribs 104).

For example, referring to FIG. 7 , each rib 104, a subset of ribs 104,or all ribs 104 may be formed of a first material 107 and a secondmaterial 109. The first material 107 may be steel and the secondmaterial 109 may be aluminum. Thus, the rib 104 may be formed of a steelbase with an aluminum deposit therearound. In FIG. 8 , each rib 104, asubset of ribs 104, or all ribs 104 may be formed of a first material110 and a second material 112. The first material 110 may be steel andthe second material 112 may be titanium. Thus, the rib 104 may be formedof a steel base with a titanium deposit therearound. The particularmakeup of the rib 104 may be selected based on the desired stiffness ata particular location around the circumference of the bearing supportassembly 100. For example, the materials of the arrangements shown inFIG. 8 may be selected to produce a higher stiffness than the materialsof the arrangements shown in FIG. 7 . In this manner, the rib of FIG. 8may be selected when it is desired to have a higher stiffness and therib of FIG. 7 may be selected when it is desired to have a lowerstiffness. For example, first rib 104 a and third rib 104 c of FIG. 5may be constructed as shown in FIG. 8 and the second rib 104 b andfourth rib 104 d of FIG. 5 may be constructed as shown in FIG. 7 . Otherarrangements of the materials of FIGS. 7 and 8 with respect to the ribs104 of FIG. 5 may be selected. Other materials may be provided alone, orin combination, to provide a desired stiffness to the ribs 104. Suchother materials may include, for example, but not limited to nickel,titanium, aluminum, or combinations thereof.

FIGS. 9 to 10C show an exemplary bearing support assembly 200. Thebearing support assembly 200 may by non-symmetric due to a hybridarrangement of solid ribs, hollow ribs, and hollow-filled ribs. Thebearing support assembly 200 includes a plurality of ribs 204 spacedcircumferentially around the bearing support assembly 200. The pluralityof ribs 204 may be located between a frame 202, also referred to as abearing support frame 202, and a bearing support 206. Points A, B, C,and D, again represent the twelve o'clock position, the three o'clockposition, the six o'clock position, and the nine o'clock position aroundthe circumference of the bearing support assembly 200.

In the example of FIGS. 9 to 10C, the stiffness around the circumferenceof the bearing support assembly 200 may be varied by altering orchanging the construction of the ribs 204. For example, the rib 204 maybe solid, hollow, or hollow filled with a filler material. Anycombination of the ribs of FIGS. 10A to 10C may be provided in a singlebearing support assembly 200 to provide a desired stiffness at variouspoints around the circumference of the bearing support assembly 200. Ahybrid beam structure may be provided around the circumference of thebearing support assembly 200 by providing a combination of hollow ribs,solid ribs, and hollow-filled ribs.

For example, in FIG. 10A, a rib 204 a may be a solid rib 210 a. In FIG.10B, a rib 204 b may be a hollow-filled rib 210 b. Within the hollow ribof the hollow-filled rib 210 b may be a material 212. The material 212may be a bi-metallic material. The hollow-filled rib 210 b may be filledwith the material 212 to vary the stiffness at different locations aboutthe circumference of the bearing support assembly 200 (FIG. 9 ). Thematerial 212 may be a high strength insert. In FIG. 10C, a rib 204 c maybe a hollow rib 210 c.

FIGS. 11 and 12 show an exemplary bearing support assembly 300. Thebearing support assembly 300 may be non-symmetric due to a hoop cut ofthe bearing support ring. The bearing support assembly 300 includes aplurality of ribs 304 spaced circumferentially around the bearingsupport assembly 300. The plurality of ribs 304 may be located between aframe 302, also referred to as a bearing support frame 302, and abearing support ring, also referred to as a bearing support 306. PointsA, B, C, and D, again represent the twelve o'clock position, the threeo'clock position, the six o'clock position, and the nine o'clockposition around the circumference of the bearing support assembly 300.The bearing support assembly 300 may support a plurality of bearings(not shown) located around the shaft 30 and between the bearing support306 and the shaft 30.

In the example of FIGS. 11 and 12 , the stiffness around thecircumference of the bearing support assembly 300 may be varied byaltering or changing the construction of the bearing support 306. Forexample, the bearing support 306 may be a split bearing support having afirst bearing support 306 a and a second bearing support 306 b. Locatedbetween a distal end of the first bearing support 306 a and a distal endof the second bearing support 306 b is a gap 307. The gap 307 may bealigned with the three o'clock position (point B) and the nine o'clockposition (point D). Thus, the stiffness K₂ of the bearing supportassembly 300 may be lower at the gap 307 than the stiffness K₁ at thefirst bearing support 306 a and/or the second bearing support 306 b. Inthis manner, the stiffness K₁ at point A and point C may be greater thanthe stiffness K₂ at point B and point D. The stiffness may decrease frompoint A as the bearing support 306 approaches the gap 307, which may bethe lowest stiffness around the circumference of the bearing support306. The gap 307 may be formed by a hoop cut in the bearing support 306to form a split or segmented bearing support. The segmentation may be atmultiple locations.

Referring to FIGS. 13 to 17C, an exemplary bearing support assembly 700is shown. The bearing support assembly 700 includes a plurality of ribs704. The ribs 704 are coupled to a frame 702, also referred to as abearing support frame 702. The ribs 704 are spaced circumferentiallyaround the bearing support assembly 700. The ribs 704 are locatedbetween a frame 702 and a bearing support 706. The ribs 704 may includefixed ribs 705 and movable ribs 707. The fixed ribs 705 may be providedin an alternating pattern with the movable ribs 707. The movable ribs707 are rotatable with respect to the frame 702. For example, whenviewing the bearing support assembly 700 in an end view, the movableribs 707 may have a vertical position 708 or a horizontal position 710.The orientation of the movable ribs 707 may be selected to provide adesired stiffness around the circumference of the bearing supportassembly 700.

For example, in FIG. 13 , a movable rib 707 at the twelve o'clockposition and at the six o'clock position may be in the horizontalposition 710. A movable rib 707 at the three o'clock position and thenine o'clock position may be in the vertical position 708. This mayresult in a higher stiffness at the horizontal position 710 than at thevertical position 708, Thus, a higher stiffness at the three o'clockposition and the nine o'clock position than at the twelve o'clockposition and the six o'clock position. In FIG. 14 , the arrangement ofthe bearing support assembly 700 may be reversed such that the movableribs 707 at the twelve o'clock position and at the six o'clock positionare in the vertical position 708. The movable ribs 707 at the threeo'clock position and the nine o'clock position are in the horizontalposition 710. This may result in a higher stiffness at the twelveo'clock position and the six o'clock position than at the three o'clockposition and the nine o'clock position. In FIG. 15 , each of the twelveo'clock position, the three o'clock position, the six o'clock position,and the nine o'clock position may be located in the horizontal position710. In FIG. 16 , each of the twelve o'clock position, the three o'clockposition, the six o'clock position, and the nine o'clock position may belocated in the vertical position 708.

In FIGS. 17A to 17C, the arrangement of the movable ribs 707 may be thesame as that shown in FIG. 14 , with the movable ribs 707 at the twelveo'clock position and at the six o'clock position are in the verticalposition 708. The movable ribs 707 at the three o'clock position and thenine o'clock position are in the horizontal position 710. The fixed ribs705 may have a cross-section that is rectangular, circular, polygonal,or other shapes. For example, the fixed ribs 705 may be rods or strips.As shown in FIG. 17C, each of the movable ribs 707 may be formed ofstacked materials. For example, the movable rib 707 of FIG. 17C may havea first material layer 722, a second material layer 724, a thirdmaterial layer 726, a fourth material layer 728, and a fifth materiallayer 730. Although five layers are described, more or fewer may beprovided. The layers may be located within a base material 720. Stackingthe layers close in a tight stack (e.g., when the gap between the layersis small) results in a higher stiffness than stacking the layers loosely(e.g., when the gap between the layers is larger than the tight stack).Therefore, the number of layers, the material of the layers, thematerial of the base material 720, the gap between the layers, or anycombination thereof may be altered to achieve a desired stiffness. Themovable ribs 707 may have a varying stiffness with respect to the loadapplied to the bearing support assembly 700 and the fixed ribs 705 mayhave a constant stiffness.

FIGS. 18 to 25 describe non-axisymmetric bearing support assemblies. Thebearing support assemblies of FIGS. 18 to 25 may have a bearing supportassembly that has a circumferential stiffness variation that isactivated after a threshold design level.

FIGS. 18 to 20 show an exemplary bearing support assembly 400. Thebearing support assembly 400 includes a plurality of ribs 404 spacedcircumferentially around the bearing support assembly 400. The pluralityof ribs 404 may be located between a frame 402, also referred to as abearing support frame 402, and a bearing support 406. Points A, B, C,and D, again represent, respectively, the twelve o'clock position, thethree o'clock position, the six o'clock position, and the nine o'clockposition around the circumference of the bearing support assembly 400.The bearing support assembly 400 may support a plurality of bearings 408located around the shaft 30.

As described previously, a stiffness may be varied around thecircumference of the bearing support assembly 400. In the example ofFIGS. 18 to 20 , the stiffness may be varied by providing a clearance orgap 412 between the frame 402 and the bearing support 406. The gap 412may be non-uniform around the circumference of the bearing supportassembly 400. The gap 412 may be varied in size around the circumferenceof the bearing support assembly 400. In some examples, the gap 412 maybe filled with a material 414 that may vary the stiffness around thecircumference of the bearing support assembly 400.

Referring to FIG. 18 , the gap 412 has a first radial distance d₁ and asecond radial distance d₂ between an outer surface of the bearingsupport 406 and an inner surface of the frame 402. The first radialdistance d₁ may be greater than the second radial distance d₂. Theradial distance increases circumferentially from the second radialdistance d₂ to the first radial distance d₁. The first radial distanced₁ may be present at point A and point C. The second radial distance d₂may be present at point B and point D. In this manner, the gap 412 maydecrease from point A to point B, increase from point B to point C,decrease from point C to point D, and increase from point D to point A.This may allow for a varying stiffness of the bearing support assembly400 in the circumferential direction.

The bearing support 406 and the frame 402 of FIGS. 18 to 20 are uniformin cross-section and uniform or symmetric in stiffness. The gap 412 isasymmetric. The larger gap (e.g., distance d₁) at point A and point Cmay allow for a softer plane or lower stiffness than the smaller gap(e.g., distance d₂) at point B and point D, which may be a largerstiffness as compared to point A and point C.

In the example of FIG. 20 , a material 414 may optionally be placedwithin the gap 412. The material 414 may be a soft material that issandwiched between the bearing support 406 and the frame 402. Thematerial 414 may be varied around the circumference of the bearingsupport assembly 400 either by varying the thickness or varying thematerial. The material 414 may be, but is not limited to, a viscoelasticmaterial, a rubber material, a shape memory alloy material, orcombinations thereof.

FIG. 21 illustrates the stiffness of the bearing support assembly 400(FIG. 18 ) as a function of the load applied to the bearing supportassembly 400. As mentioned, the stiffness of the bearing supportassembly 400 is load dependent and varies along the circumference. Forexample, since the distance d₂ is smaller at point B and point D, when aload is applied at these points, the bearing support 406 will come incontact with the frame sooner than when the same load is applied atpoint A and at point C. This is shown in FIG. 21 via an X-axis curve 458and a Y-axis curve 456. The X-axis curve 458 represents the stiffness ofthe bearing support assembly 400 at point B and point D (FIG. 18 ). TheY-axis curve 456 represents the stiffness of the bearing supportassembly 400 at point A and point C (FIG. 18 ). A line 454 represents amean stiffness of the bearing support assembly, a line 450 represents astiffness above the mean stiffness and a line 452 represents a stiffnessbelow the mean stiffness. In FIG. 21 , as a load is applied to thebearing support assembly, all points around the bearing support assemblywill exhibit the same stiffness. This is because, referring to FIG. 18 ,neither of the distances d₁ or d₂ have been closed to close the gap 412.At point L₁, (e.g., a threshold load level) the load continues toincrease and the gap 412 continues to shrink. At point L₃, the gap 412at point B and point D in FIG. 3 , the gap 412 is closed and the bearingsupport 406 and the frame 402 are touching. This results in a highstiffness, i.e., a stiffness above the mean stiffness. At point L₂, thegap 412 at point B and point D is closed, but the gap 412 at point A andpoint C is still present. This results in a low stiffness, i.e., astiffness below the mean stiffness.

FIGS. 22 to 24 show an exemplary bearing support assembly 500. Thebearing support assembly 500 includes a plurality of ribs 504 spacedcircumferentially around the bearing support assembly 500. The pluralityof ribs 504 may be located between a frame 502, also referred to as abearing support frame 502, and a bearing support 506. Points A, B, C,and D, again represent, respectively, the twelve o'clock position, thethree o'clock position, the six o'clock position, and the nine o'clockposition around the circumference of the bearing support assembly 500.The bearing support assembly 500 may support a plurality of bearings 508located around the shaft 30.

As described previously, a stiffness may be varied around thecircumference of the bearing support assembly 500. In the example ofFIGS. 22 and 23 , the stiffness may be varied by providing a clearanceor gap 512 between the frame 502 and the bearing support 506. The gap512 may be uniform around the circumference of the bearing supportassembly 500. The gap 512 may be filled with a first material 514 and asecond material 513 that may vary the stiffness around the circumferenceof the bearing support assembly 500. The first material 514 and thesecond material 513 may have a changing stiffness that varies 360°circumferentially. For example, the first material 514 and/or the secondmaterial 513 may be a shape memory alloy. The material, e.g., the shapememory alloy, may have a varying stiffness.

The bearing support assembly 500 may be a symmetric bearing support witha non-symmetric system stiffness. As shown in FIG. 22 , thenon-symmetric stiffness may be achieved by providing a first material514 having a first stiffness and a second material 513 having a secondstiffness. In some examples, the first stiffness may be greater than thesecond stiffness. In some examples, the first stiffness may be lesserthan the second stiffness. For example, in FIG. 18 , the first stiffnessmay be lesser than the second stiffness, such that stiffness at point Aand point C is lower than the stiffness at point B and point D, as isdescribed with respect to FIG. 20 .

FIG. 24 shows another manner to vary the stiffness of the materiallocated in the gap 512 between the frame 502 and the bearing support 506around the circumference of the bearing support assembly 500 (FIG. 22 ).In FIG. 24 , the gap 512 may have a bellows 520 located therein. Withinthe bellows 520 may be located a spring 522, a magnetorheological (MR)fluid 526, and a coil 524. The MR fluid 526 may be a non-newtonianfluid. FIG. 24 may be a fluid damper with varying stiffness in thecircumferential direction. As a load is applied to the bellows 520 tocompress the spring 522, the MR fluid 526 is also compressed. As theload increases and the MR fluid 526 is increasingly being compressed, ina first direction (e.g., at point B and point D), the stiffness mayincrease with respect to a second direction (e.g., at point A and pointC).

FIG. 25 illustrates the stiffness of the bearing support assembly 500(FIG. 22 ) as a function of the load applied to the bearing supportassembly 500. The graph will appear the same for either varying thematerial stiffness as in the arrangement in FIG. 23 or as in thearrangement in FIG. 24 . As mentioned, the stiffness of the bearingsupport assembly 500 is load dependent and varies along thecircumference. For example, since the material stiffness changes in thecircumferential direction, when a load is applied, the bearing support406 will come in contact with the frame sooner at points where thematerial stiffness is less (e.g., at point B and point D) than when thesame load is applied where the material stiffness is greater (e.g., atpoint A and at point C). This is shown in FIG. 25 via an X-axis curve558 and a Y-axis curve 556. The X-axis curve 558 represents thestiffness of the bearing support assembly 500 at point B and point D(FIG. 22 ). The Y-axis curve 556 represents the stiffness of the bearingsupport assembly 500 at point A and point C (FIG. 22 ). A line 554represents a mean stiffness of the bearing support assembly, a line 550represents a stiffness above the mean stiffness, and a line 552represents a stiffness below the mean stiffness.

In FIG. 25 , as a load is applied to the bearing support assembly, allpoints around the bearing support assembly will exhibit the samestiffness. This is because the material at all points accommodates theload. At point L₁, the load continues to increase and the softermaterial at point B and point D begins to compress, resulting inincreased stiffness as shown in curve 558. As the softer materialcompresses, the point B and point D take on more of the load and thestiffness at point A and point C begins to decrease. At point L₂, thematerial at point B and point D is fully compressed and a maximumstiffness is experienced until point L₃ when the load applied hascompressed the material at points A and point C such that the stiffnessat all points equals out again at point L₄. On the other hand, at pointL₅, due to compression of the material at points B and point D, the loadexperienced by point A and point C is lowered until point L₆ where thestiff is equalized as described previously.

FIGS. 26 and 27 describe a bi-linear circumferential stiffness variationthat is activated after a threshold level. A bearing assembly 600 ofFIG. 26 has a bearing support 606 and a frame 602, also referred to as abearing support frame 602. The frame 602 has a spring finger 603. Thebearing support 606 has a spring finger 605. A gap 612 between thebearing support 606 and the frame 602 may be uniform. One or morebearings 608 may be supported between the shaft 30 and the bearingsupport 606. Each of the bearing support 606 and the frame 602 may haveasymmetric stiffness.

FIG. 27 shows an X-axis curve 658 and a Y-axis curve 656. The X-axiscurve 658 represents the stiffness of the bearing support assembly 600at point B and point D (e.g., FIG. 22 ). The Y-axis curve 656 representsthe stiffness of the bearing support assembly 600 at point A and point C(e.g., FIG. 22 ). A line 654 represents a mean stiffness of the bearingsupport assembly, a line 650 represents a stiffness above the meanstiffness and a line 652 represents a stiffness below the meanstiffness.

In FIG. 27 , it can be seen that the X-axis location of the bearingsupport assembly 600 will always have a greater stiffness than theY-axis location of the bearing support assembly 600. At the X-axis, as aload is applied to the bearing support assembly 600, the bearing supportassembly 600 exhibits a first stiffness. When the gap 612 closes, atload L₁, the stiffness at the X-axis location increases to the line 650at load L₂, which may be the maximum stiffness. At the Y-axis, as a loadis applied to the bearing support assembly, the bearing support assembly600 exhibits a first stiffness. When the gap 612 closes, at load L₃, thestiffness at the Y-axis location decreases to the line 652 at load L₄,which may be the minimum stiffness, due to the closing of the gap 612 atthe Y-axis location.

FIGS. 28 to 32 show examples of non-axisymmetric supports. The examplesof FIGS. 28 to 32 may have cross sections of varying thickness. Forexample, in FIG. 28 , a bearing support 806 have a cross section isvarying in thickness. The bearing support 806 of FIG. 28 is alwaysnon-symmetric. The bearing support 806 may have an inner diameter 812and an outer diameter 814. At the inner diameter 812, the cross sectionmay be circular. At the outer diameter 814, the cross section may beovular or elliptical. Points A, B, C, and D, again represent,respectively, the twelve o'clock position, the three o'clock position,the six o'clock position, and the nine o'clock position around thecircumference of the bearing support 806. At the position of A and C,the cross section has a maximum thickness and at the position of B andD, the cross section has a minimum thickness. From point A to point B,the thickness of the cross section gradually decreases to point B, thenincreases to point C, decreases to point D, and, finally, increases topoint A. This allows for varying the stiffness around the bearingsupport 806. As mentioned previously, the variation may be any of thevariations described with respect to FIGS. 4A to 4D.

In FIG. 29 , a bearing support 906 a may have an inner diameter 912 andan outer diameter 914. At the inner diameter 912, the cross section maybe circular. At the outer diameter 914, the cross section may be ovularor elliptical. The bearing support 906 a of FIG. 29 is non-symmetriconly during high loads and is symmetric in nominal loads. This is due toa gap 918. At high loads, the gap 918 at point B and point D will beclosed resulting in a higher stiffness than at point A and point C wherethe gap 918 is still open. Below the load at which the gap 918 is closedat point B and point D, however, the stiffness will be symmetric sinceall points will exhibit the same stiffness.

FIGS. 30 to 32 show a bearing support assembly 1000. In FIG. 31 , abearing support assembly 1000 a may always be non-symmetric and, in FIG.32 , a bearing support assembly 1000 b may be non-symmetric only duringhigh loads and may be symmetric at nominal loads. Referring to FIG. 30 ,the bearing support assembly 1000 (which may also be the bearing supportassembly 1000 a and the bearing support assembly 1000 b) has a frame1002, also referred to as a bearing support frame 1002, a bearingsupport 1006, and bearings 1008. The bearing support assembly 1000 alsoincludes a bearing supplemental support 1020. The bearing supplementalsupport 1020 may be placed non-axisymmetrically to vary the stiffnessaround the circumference of the bearing support assembly 1000. Forexample, in FIG. 31 , a bearing supplemental support 1020 a may beplaced radially inward and outward between the frame 1002 and thebearing support 1006. When the members of the bearing supplementalsupport 1020 a are present (e.g., in the trapezoidal area), thestiffness may be higher than at locations with no members. In FIG. 32 ,a bearing supplemental support 1020 b may be placed such that a gap 1018exists between the bearing supplemental support 1020 b and the bearingsupport 1006. In this manner, the non-symmetric stiffness occurs onlywhen the load has increased past a point at which the gap 1018 isclosed, activating the members of the bearing supplemental support 1020b in a manner similar to that shown in FIG. 31 .

Accordingly, the bearing support assemblies of the present disclosureallow for varying the stiffness of the bearing support assembly. Thisresults in a desired directional stiffness of the bearing supportassembly. This further results in a desired active support of thebearings on the shaft at various locations around the circumference ofthe bearing support assembly based on the particular stiffness at thatlocation.

The stiffness referred to herein is the stiffness K of a body that ismeasured in Newtons per meter or pounds per inch. That is, the stiffnessis the engineering stiffness that represents the resistance of anelastic body to deflection or deformation by an applied force.

The terms “coupled,” “fixed,” “attached to,” “connected,” and the like,refer to both direct coupling, fixing, attaching, or connecting, as wellas indirect coupling, fixing, attaching, or connecting, through one ormore intermediate components or features, unless otherwise specifiedherein.

Further aspects of the present disclosure are provided by the subjectmatter of the following clauses.

A bearing support assembly configured to support one or more bearings ona shaft including a bearing support frame configured to be coupled to astatic frame, a plurality of ribs connected to the bearing supportframe, and a bearing support connected to the plurality of ribs andconfigured to support a bearing, wherein the bearing support assemblyhas a non-axisymmetric stiffness varying around a circumference of thebearing support assembly.

The bearing support assembly of any preceding clause, wherein thebearing support assembly always has a non-axisymmetric stiffness aroundthe circumference of the bearing support assembly.

The bearing support assembly of any preceding clause, wherein thebearing support assembly has a non-axisymmetric stiffness above athreshold load level and a symmetric stiffness below the threshold loadlevel.

The bearing support assembly of any preceding clause, wherein thenon-axisymmetric stiffness is a sinusoidal curve, a linear curve, aspline, or combinations thereof.

The bearing support assembly of any preceding clause, wherein thebearing support frame has a twelve o'clock position, a three o'clockposition, a six o'clock position, and a nine o'clock position, andwherein a stiffness of the bearing support frame is greater at thetwelve o'clock position and the six o'clock position than at the threeo'clock position and the nine o'clock position.

The bearing support assembly of any preceding clause, wherein thebearing support frame has a twelve o'clock position, a three o'clockposition, a six o'clock position, and a nine o'clock position, andwherein a stiffness of the bearing support frame is lower at the twelveo'clock position and the six o'clock position than at the three o'clockposition and the nine o'clock position.

The bearing support assembly of any preceding clause, wherein thebearing support frame has a stiffness at an X-axis that is greater thana stiffness at a Y-axis.

The bearing support assembly of any preceding clause, wherein thebearing support frame has a stiffness at an X-axis that is lower than astiffness at a Y-axis.

The bearing support assembly of any preceding clause, thenon-axisymmetric stiffness is achieved by altering a material of one ormore of the plurality of ribs.

The bearing support assembly of any preceding clause, wherein theplurality of ribs comprises a first subset of ribs and a second subsetof ribs, and wherein a material of the first subset of ribs is differentthan a material of the second subset of ribs.

The bearing support assembly of any preceding clause, wherein thematerial of the first subset of ribs is a steel base with an aluminumdeposit outer layer and the material of the second subset of ribs is asteel base with a titanium deposit outer layer.

The bearing support assembly of any preceding clause, wherein theplurality of ribs comprises a hybrid rib arrangement.

The bearing support assembly of any preceding clause, wherein the hybridrib arrangement comprises a combination of solid ribs, hollow ribs,hollow-filled ribs, or any combination thereof.

The bearing support assembly of any preceding clause, wherein thenon-axisymmetric stiffness is achieved by altering the bearing support.

The bearing support assembly of any preceding clause, wherein thebearing support comprises a first bearing support separated by a gapfrom a second bearing support.

The bearing support assembly of any preceding clause, wherein the gapincludes a first gap and a second gap, the first gap between a firstdistal end of the first bearing support and a first distal end of thesecond bearing support and the second gap between a second distal end ofthe first bearing support and a second distal end of the second bearingsupport.

The bearing support assembly of any preceding clause, wherein thebearing support is a split bearing support.

The bearing support assembly of any preceding clause, further comprisinga nonsymmetric gap between the bearing support and the bearing supportframe.

The bearing support assembly of any preceding clause, further comprisinga material in the nonsymmetric gap.

The bearing support assembly of any preceding clause, wherein thematerial is a viscoelastic material, a rubber material, a shape memoryalloy, or combinations thereof.

The bearing support assembly of any preceding clause, wherein a firststiffness at an X-axis location is greater than a second stiffness at aY-axis location above a threshold load level, and the first stiffness isthe same as the second stiffness below the threshold load level.

The bearing support assembly of any preceding clause, further comprisinga symmetric gap between the bearing support and the bearing supportframe.

The bearing support assembly of any preceding clause, wherein thesymmetric gap is filled with a first material and a second material, thefirst material having a greater stiffness than that of the secondmaterial.

The bearing support assembly of any preceding clause, further comprisinga symmetric gap between the bearing support and the bearing supportframe, wherein the symmetric gap is filled with a magnetorheologicalfluid.

The bearing support assembly of any preceding clause, wherein thebearing support frame has a first spring finger adjacent a second springfinger on the bearing support.

The bearing support assembly of any preceding clause, further comprisinga gap between the bearing support frame and the bearing support.

The bearing support assembly of any preceding clause, wherein thenon-axisymmetric stiffness is achieved by altering an orientation of oneor more of the plurality of ribs.

The bearing support assembly of any preceding clause, wherein theplurality of ribs includes a plurality of fixed ribs and a plurality ofmovable ribs.

The bearing support assembly of any preceding clause, wherein theplurality of movable ribs is arranged vertically with respect to aY-axis.

The bearing support assembly of any preceding clause, wherein theplurality of movable ribs is arranged horizontally with respect to anX-axis.

The bearing support assembly of any preceding clause, wherein a firstsubset of the plurality of movable ribs is arranged vertically withrespect to a Y-axis and a second subset of the plurality of movable ribsis arranged horizontally with respect to an X-axis.

The bearing support assembly of any preceding clause, wherein the firstsubset is aligned with a twelve o'clock position and a six o'clockposition and the second subset is aligned with a three o'clock positionand a nine o'clock position.

The bearing support assembly of any preceding clause, wherein the firstsubset is aligned with a three o'clock position and a nine o'clockposition and the second subset is aligned with a twelve o'clock positionand a six o'clock position.

The bearing support assembly of any preceding clause, wherein one ormore of the plurality of movable ribs is formed of layers of materialwithin a base material.

The bearing support assembly of any preceding clause, wherein thenon-axisymmetric stiffness is achieved by altering a cross section ofthe bearing support.

The bearing support assembly of any preceding clause, wherein the crosssection is non-symmetric such that an outer diameter of the bearingsupport is ovular and an inner diameter of the bearing support iscircular.

The bearing support assembly of any preceding clause, further comprisinga bearing supplemental support connected between the bearing supportframe and the bearing support.

The bearing support assembly of any preceding clause, wherein thebearing supplemental support comprises a plurality of members extendingbetween the bearing support frame and the bearing support.

A compressor section of a gas turbine engine including a shaft fordriving a compressor, a static frame, a bearing, and a bearing supportassembly coupled between the static frame and the shaft. The bearingsupport assembly including a bearing support frame coupled to the staticframe, a plurality of ribs connected to the bearing support frame, and abearing support connected to the plurality of ribs and configured tosupport the bearing, wherein the bearing support assembly has anon-axisymmetric stiffness around a circumference of the bearing supportassembly.

Although the foregoing description is directed to the preferredembodiments, it is noted that other variations and modifications will beapparent to those skilled in the art, and may be made without departingfrom the spirit or scope of the disclosure Moreover, features describedin connection with one embodiment may be used in conjunction with otherembodiments, even if not explicitly stated above.

The invention claimed is:
 1. A bearing support assembly configured tosupport one or more bearings on a shaft, the bearing support assemblycomprising: a bearing support frame configured to be coupled to a staticframe; a plurality of ribs connected to the bearing support frame; and abearing support connected to the plurality of ribs and configured tosupport a bearing of the one or more bearings, wherein the bearingsupport assembly has a non-axisymmetric stiffness varying around acircumference of the bearing support assembly, and wherein thenon-axisymmetric stiffness is achieved by altering a material of one ormore of the plurality of ribs.
 2. The bearing support assembly of claim1, wherein the bearing support assembly always has a non-axisymmetricstiffness around the circumference of the bearing support assembly. 3.The bearing support assembly of claim 1, wherein the bearing supportassembly has a non-axisymmetric stiffness above a threshold load leveland a symmetric stiffness below the threshold load level.
 4. The bearingsupport assembly of claim 1, wherein the non-axisymmetric stiffness is asinusoidal curve, a linear curve, a spline, or combinations thereof. 5.A bearing support assembly configured to support one or more bearings ona shaft, the bearing support assembly comprising: a bearing supportframe configured to be coupled to a static frame; a plurality of ribsconnected to the bearing support frame; and a bearing support connectedto the plurality of ribs and configured to support a bearing of the oneor more bearings, wherein the bearing support assembly has anon-axisymmetric stiffness varying around a circumference of the bearingsupport assembly, and wherein the non-axisymmetric stiffness is achievedby altering an orientation of one or more of the plurality of ribs,wherein the plurality of ribs includes a plurality of fixed ribs and aplurality of movable ribs.
 6. The bearing support assembly of claim 1,wherein the plurality of ribs comprises a first subset of ribs and asecond subset of ribs, and wherein a material of the first subset ofribs is different than a material of the second subset of ribs, andwherein the material of the first subset of ribs is a steel base with analuminum deposit outer layer and the material of the second subset ofribs is a steel base with a titanium deposit outer layer.
 7. The bearingsupport assembly of claim 1, wherein the plurality of ribs comprises ahybrid rib arrangement, and wherein the hybrid rib arrangement comprisesa combination of solid ribs, hollow ribs, hollow-filled ribs, or anycombination thereof.
 8. The bearing support assembly of claim 1, whereinthe non-axisymmetric stiffness is achieved by altering the bearingsupport, wherein the bearing support comprises a first bearing supportseparated by a gap from a second bearing support and the gap includes afirst gap and a second gap, the first gap between a first distal end ofthe first bearing support and a first distal end of the second bearingsupport and the second gap between a second distal end of the firstbearing support and a second distal end of the second bearing support,and wherein the bearing support is a split bearing support.
 9. Thebearing support assembly of claim 1, further comprising a nonsymmetricgap between the bearing support and the bearing support frame; and amaterial in the nonsymmetric gap, wherein the material is a viscoelasticmaterial, a rubber material, a shape memory alloy, or combinationsthereof, and wherein a first stiffness at an X-axis location is greaterthan a second stiffness at a Y-axis location above a threshold loadlevel, and the first stiffness is the same as the second stiffness belowthe threshold load level.
 10. The bearing support assembly of claim 1,further comprising a symmetric gap between the bearing support and thebearing support frame, wherein the symmetric gap is filled with a firstmaterial and a second material, the first material having a greaterstiffness than that of the second material.
 11. The bearing supportassembly of claim 1, further comprising a symmetric gap between thebearing support and the bearing support frame, wherein the symmetric gapis filled with a magnetorheological fluid.
 12. The bearing supportassembly of claim 1, wherein the bearing support frame has a firstspring finger adjacent a second spring finger on the bearing support;and a gap between the bearing support frame and the bearing support. 13.The bearing support assembly of claim 1, wherein the non-axisymmetricstiffness is achieved by altering a cross section of the bearingsupport, and wherein the cross section is non-symmetric such that anouter diameter of the bearing support is ovular and an inner diameter ofthe bearing support is circular.
 14. The bearing support assembly ofclaim 1, further comprising a bearing supplemental support connectedbetween the bearing support frame and the bearing support, wherein thebearing supplemental support comprises a plurality of members extendingbetween the bearing support frame and the bearing support.
 15. Thebearing support assembly of claim 1, wherein the non-axisymmetricstiffness is achieved by altering an orientation of one or more of theplurality of ribs, wherein the plurality of ribs includes a plurality offixed ribs and a plurality of movable ribs.
 16. The bearing supportassembly of claim 5, wherein one or more of the plurality of movableribs is formed of layers of material within a base material.
 17. Thebearing support assembly of claim 5, wherein the plurality of movableribs is arranged vertically with respect to a Y-axis, horizontally withrespect to an X-axis, or wherein a first subset of the plurality ofmovable ribs is arranged vertically with respect to a Y-axis and asecond subset of the plurality of movable ribs is arranged horizontallywith respect to an X-axis.
 18. The bearing support assembly of claim 17,wherein the first subset of the plurality of movable ribs is alignedwith a twelve o'clock position and a six o'clock position and the secondsubset of the plurality of movable ribs is aligned with a three o'clockposition and a nine o'clock position.
 19. The bearing support assemblyof claim 17, wherein the first subset of the plurality of movable ribsis aligned with a three o'clock position and a nine o'clock position andthe second subset of the plurality of movable ribs is aligned with atwelve o'clock position and a six o'clock position.
 20. A compressorsection of a gas turbine engine, the compressor section comprising: (a)a shaft for driving a compressor; (b) a static frame; (c) a bearing; and(d) a bearing support assembly coupled between the static frame and theshaft, the bearing support assembly comprising: (i) a bearing supportframe coupled to the static frame; (ii) a plurality of ribs connected tothe bearing support frame; and (iii) a bearing support connected to theplurality of ribs and configured to support the bearing, wherein thebearing support assembly has a non-axisymmetric stiffness around acircumference of the bearing support assembly, and wherein thenon-axisymmetric stiffness is achieved by altering a material of one ormore of the plurality of ribs.